1. Field of the Invention
The invention relates to a method for the preparation of regenerable dielectric layers through polymerization of gases by means of a glow discharge on a substrate, especially for the preparation of electric multi-layer capacitors, in which monomeric perfluoro-hydrocarbons having the empirical formula (CF.sub.2).sub.n, wherein n=2 to 10 and/or the corresponding perfluorized cyclic alkanes are blown into the region of the glow discharger.
2. Description of the Prior Art
DE-A No. 29 07 775 discloses a method for the preparation of dielectric layers of glow polymerisate, in which high temperature-resistant dielectric layers are prepared from starting monomers which are present in the form of a mixture of perfluorized hydrocarbon and unsubstituted dienes. The term monomer in this context means a molecule or a compound of relatively low molecular weight and simple structure which is converted into polymer form under the influence of a glow discharge by forming a bond with itself or similar molecules or compounds.
The glow polymerization is carried out at the pressure of about 0.2 to 2 mbar and a frequency of applied voltage of over 5 MHz.
The multi-layer capacitors mentioned at the outset are produced by generating on a substrate alternatingly thin, vapor-deposited or sputtered-on metal layers and the glow-polymer dielectric layers. It has been found, however, with the known high temperature-resistant dielectric layers, that they are sensitive to immersion soldering and can easily be damaged mechanically in the process. Those dielectric areas over which vapor-deposited or sputtered-on metal coatings have been applied are particularly critical.